title: Risk factors for adverse outcomes in spontaneous versus assisted conception twin pregnancies.
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011256:Pregnancy Outcome; D018566:Pregnancy, High-Risk; D012016:Reference Values; D027724:Reproductive Techniques, Assisted / Q000009:adverse effects* / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012307:Risk Factors; D014427:Twins / Q000706:statistics & numerical data*